Joint ratio estimation and weights detection in closed loop transmit diversity

ABSTRACT

A communications device configured to extract weighting factors from incoming signals received from two or more antennas while estimating a channel ratio for the signals. The device includes at least one antenna and a digital signal processor. The method includes receiving two signals and extracting the weighting factors while estimating the channel ratio.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates generally to wireless systems and moreparticularly to determining ratio estimations and weightings formulti-antenna verification.

2. Background Information

The increasing use of wireless communications leads to a need forclearer transmissions using less to do more. The move to multipleantenna systems has caused a need for new ways to balance transmissionsover more than one antenna to one or more receiving antennas. In somecases, weighting factors may be used for balancing the transmissions. Itis thus desirable to implement a convenient way to determine weightingfactors from a received transmission to maximize some transmissioncondition, such as a maximized signal to noise ratio.

SUMMARY OF THE INVENTION

According to one embodiment of the present invention, a device isprovided. The device includes at least one antenna and a digital signalprocessor. The antenna is capable of receiving a first signal from afirst antenna and a second signal from a second antenna. The digitalsignal processor is configured to extract a first weighting factor and asecond weighting factor from the first signal and the second signalwhile estimating a channel ratio for the first signal and the secondsignal.

Notation and Nomenclature

Certain terms are used throughout the following description and claimsto refer to particular system components. As one skilled in the art willappreciate, different companies may refer to a component by differentnames. This document does not intend to distinguish between componentsthat differ in name but not function. In the following discussion and inthe claims, the terms “including” and “comprising” are used in anopen-ended fashion, and thus should be interpreted to mean “including,but not limited to . . . ”. Also, the term “couple” or “couples” isintended to mean either an indirect or direct connection. Thus, if afirst device couples to a second device, that connection may be througha direct connection, or through an indirect connection via other devicesand connections.

I. BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the preferred embodiments of thepresent invention, reference will now be made to the accompanyingdrawings, wherein:

FIGS. 1A and 1B shows a diagram of a system in accordance with preferredembodiments of the invention and including a transmitter with multipleantennas and a receiver;

FIGS. 2A and 2B depicts an exemplary embodiment of a transmission flowdiagram; and

FIG. 3 depicts an exemplary embodiment of a reception flow diagram.

II. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following discussion is directed to various embodiments of theinvention. Although one or more of these embodiments may be preferred,the embodiments disclosed should not be interpreted, or otherwise used,as limiting the scope of the disclosure, including the claims, unlessotherwise specified. In addition, one skilled in the art will understandthat the following description has broad application, and the discussionof any embodiment is meant only to be exemplary of that embodiment, andnot intended to intimate that the scope of the disclosure, including theclaims, is limited to that embodiment.

Referring now to FIGS. 1A and 1B, communications system 100 is shown, inaccordance with a preferred embodiment of the invention. As shown, thecommunications system 100 includes at least one base station 105, ortransmitter 105, preferably coupled to a network 95, and acommunications device 155, or receiver 155. In various embodiments, thebase station 105 may include a transmitter and a receiver, while thecommunications device 155 may also include a transmitter and a receiver.

As shown in FIG. 1A, the base station 105 includes an input/output (I/O)block 110, a digital signal processor (DSP) block 115, ascrambler/descrambler (S/D) 120, a plurality of RF units 125A and 125B,and a plurality of antennas 130A and 130B. As shown in FIG. 1A, the I/Oblock 110 is coupled to the DSP block 115. The DSP block 115 is coupledto the S/D 120. The S/D 120 is coupled to the RF units 125A and 125B.The RF unit 125A is coupled to the first antenna 130A. The RF unit 125Bis coupled to the second antenna 130B.

As shown in FIG. 1B, the communications device 155 includes aninput/output (I/O) block 185, a digital signal processing (DSP) block180, a scrambler/descrambler (S/D) 170, an RF unit 165, and an antenna160. As shown in FIG. 1B, the antenna 160 is coupled to the RF unit 165.The RF unit 165 is coupled to the S/D 170. The S/D 170 is coupled to theDSP block 180. The DSP block 180 is coupled to the I/O block 185.

As used herein, an I/O block, such as I/O block 110 and/or I/O block185, may include any one or more of a digital, analog, visual, optical,tactile, electronic, electrical, voice, and/or sonic input or outputdevice or devices for interfacing with a person, electronic device,system, or network. As used herein, a DSP block 115 and/or DSP block 180may include a digital signal processor chip, or chips, a controller, amicrocontroller, a processor, a microprocessor, and/or configuredhardware, firmware, or software. As used herein, the S/D 120 and/or S/D170 may include separate or integrated scrambler and descrambler, wheneach is present. The network 95 may include any communications,electronic, and/or optical network carrying voice, audio, video,commands, instructions, data or any combination thereof.

The communications system 100 may be representative of, or adapted to, awide variety of electronic systems. An exemplary electronic system maycomprise a battery-operated, mobile cell phone 155 and base station 105,such as is configured to operate using third generation methods such asW-CDMA (from 3GPP). As such, the cell phone 155 may include a keypad,display, microphone, and speaker in the I/O block 185.

Referring now to FIG. 2, an exemplary embodiment of a transmission flowdiagram 200, according to a preferred embodiment of the presentinvention is shown. In the embodiment shown, the transmission flow isfor a W-CDMA configured system. Other embodiments for other systemsusing other configurations are also contemplated. As shown in FIG. 2, adedicated physical control channel (DPCCH) 205 and a dedicated physicaldata channel (DPDCH) 210 are provided to a dedicated physical channel(DPCH) 215. The DPCH 215 provides a signal 217 to a combiner 225 thatcombines the signal 217 with an spread and/or scramble signals 220. Thespread/scrambled signal 227 is provided to a first combiner 235A alongwith a first weighting factor w₁ 230A. The weighted signal 237A isprovided to a summer 245A for combination with common pilot signals(CPICH₁) 240A. The weighted pilot signals 247A are provided to a firstantenna 130A for transmission.

The spread/scrambled signal 227 is also provided to a second combiner235B along with a second weighting factor w₂ 230B. The weighted signal237B is provided to a summer 245B for combination with common pilotsignals (CPICH₂) 240B. The weighted pilot signals 247B are provided to asecond antenna 130B for transmission. As shown in FIG. 2, the firstweighting factor w₁ 230A and the second weighting factor w₂ 230B aregenerated in block 275 from a signal 272 extracted from the feedbackindicator (FBI) field message 265 received in the DPCCH from thereceiver in block 270.

Note that the operations performed in blocks 230, 325, 330, 335, and/or340 may be performed in the DSP block 115. Some or all of the operationsperformed in blocks 230, 325, 330, 335, and/or 340 may also be performedin separate software routines or in separate, dedicated hardware.

Referring now to FIG. 3, an exemplary embodiment of a reception flowdiagram is shown, according to a preferred embodiment of the presentinvention. As shown in FIG. 3, a signal 307 is received at an antenna305. The signal 307 is provided to an RF unit 310, which downconvertsthe signal 307 to the baseband as signal 312. The signal 312 isdescrambled and despreaded in block 315 to create signals 317, 318, and319.

The signal 317 represents the common pilot symbols used for commonchannel estimation in block 320 to create signals 322 and 324, each anestimate of the channels g₁(n) and g₂(n). The channel estimates g₁(n)and g₂(n), signal 324, along with the dedicated pilot symbols (y(n)),signal 318, are used to do the phase detection. The dedicated physicaldata channel (DPDCH) 316 is provided to the MRC (Maximum Ratio Combiner)325. According to a preferred embodiment of the present invention, thejoint weights and ratio estimation is done inside the phase detector.The output of the phase detector, signal 337, is a combination of afirst weighting factor w₁ 230A and a second weighting factor w₂ 230B,i.e., one of 16 combinations of possible w₁ and w₂ in this embodiment,where w₁ and w₂ are complex. In some embodiments, one of w₁ and w₂ maybe complex while the other is real. In general, the weighting factorsare complex valued signals, i.e., w_(i)=a_(i)+jb_(i).

The channel estimates, g₁(n) and g₂(n), signal 322, and the weightingfactors w₁ and w₂ 327 are provided to the MRC 325 to generate thechannel estimate, h(n), to be used in the MRC. The output of the MRC,signal 337, is provided to the decoder 330. The common pilot signals 319are provided to the FBI generation block 340 by the block 315, where theFBI bit or bits 345 are generated to be sent to the base station.

Operation of the communications system 100 may be performed in closedloop transmit diversity as in non-diversity for channel coding,interleaving and/or spreading. The spread and preferably complex valuedsignal may be fed to both transmit antennas 130A and 130B. Each signalis typically weighted with an antenna specific weighting factor, w₁ orw₂.

In one embodiment, the weighting factors w₁ and w₂ are correspondingphase adjustments in closed loop mode 1 and phase and amplitudeadjustments in closed loop mode 2. The weighting factors to be used in atransmission may be determined by the device 155 and transmitted to thebase station 105 using the FBI field. In one embodiment, in the closedloop mode 1, different orthogonal dedicated pilot symbols in the DPCCHare sent using the two different antennas 130A and 130B. For closed loopmode 2 the same dedicated pilot symbols in the DPCCH are sent on bothantennas 130A and 130B. There are two closed loop modes whosecharacteristics are summarized in the Table 1. The use of the modes iscontrolled via higher layer signaling.

TABLE 1—Summary of number of feedback information bits per slot,N_(FBD), feedback command length in slots, N_(W), feedback command rate,feedback bit rate, number of phase bits, N_(PH), per signalling word,number of amplitude bits, N_(PO), per signalling word and amount ofconstellation rotation at the device for the two closed loop modes

Closed Constel- Loop Update Feedback lation Mode N_(FBD) N_(W) Rate BitRate N_(PO) N_(PH) Rotation 1 1 1 1500 Hz 1500 bps 0 1 π/2 2 1 4 1500 Hz1500 bps 1 3 N/A

For both modes, orthogonal common pilot (CPICH) symbols are sent fromtwo antennas 130A and 130B. Note that no weights are applied to theCPICH symbols. At the receiver 155, in order to perform the MRCoperations, we need to estimate the channel gain h(n).h(n)=w ₁(n)h ₁(n)+w ₂(n)h ₂(n)  (1)where h_(i)(n) are the stacked (column vector) channel gains from theith antenna 130 i to the device 155 via different paths at the nth slot.In one embodiment, there are 15 slots per frame with 100 frames persecond. There are at least two options to estimate h(n):

1. Channel estimation using the dedicated pilot symbols only, or

2. Channel estimation using both the dedicated pilot symbols and theCPICH symbols. It has previously been shown that the first option doesnot provide a satisfying performance for both modes. Simulations verifythis result.

Thus, for antenna verification option 2 is needed for both modes whereh_(i)(n) are estimated from the CPICH symbols as g(n):g(n)=w ₁(n)g ₁(n)+w ₂(n)g ₂(n)  (2)with g_(i)(n) being proportional to h_(i)(n). To detect the weightingfactors, we will use the dedicated pilot symbols and the channelestimate from the CPICH symbols.

After despreading, the received signal for DPCH dedicated pilot symbolsfor the mode 2 can be written as:y _(d2)(n,i)=b _(i)(w ₁ h ₁(n)+w ₂ h ₂(n))+n(n,i)  (3)where b_(i) are the dedicated pilot symbols. Note that for mode 2, thededicated pilot symbols are the same for both antennas 130A and 130B.

From equation 3, we can derive the joint probability density function(PDF) of y_(d2)(n,i) conditioned on the weights w_(i). Define y(n):y(n)=[y _(d2)(n,1)y _(d2)(n,2) . . . y _(d2)(n,K)]^(T)  (4)Then it can be shown that

$\begin{matrix}{{p\left( {y❘w} \right)} = {\frac{1}{\pi^{M}{\det(C)}}{\mathbb{e}}^{\lbrack{{- {({{y{(n)}} - {\mu_{2}{(n)}}})}^{H}}{C^{- 1}{({{y{(n)}} - {\mu_{2}{(n)}}})}}}\rbrack}}} & (5)\end{matrix}$where C, a diagonal variance matrix, is given by

$\begin{matrix}{C = \begin{bmatrix}\sigma_{1}^{2} & \; & \; & \; & \; & \; & \; & \; & \; & \; \\\; & \sigma_{2}^{2} & \; & \; & \; & \; & \; & \; & \; & \; \\\; & \; & \cdots & \; & \; & \; & \; & \; & \; & \; \\\; & \; & \; & \sigma_{L}^{2} & \mspace{11mu} & \; & \; & \; & \; & \; \\\; & \; & \; & \; & \sigma_{1}^{2} & \; & \; & \; & \; & \; \\\; & \; & \; & \; & \; & \sigma_{2}^{2} & \; & \; & \; & \; \\\; & \; & \; & \; & \; & \; & \cdots & \; & \; & \; \\\; & \; & \; & \; & \; & \; & \; & \sigma_{L}^{2} & \; & \; \\\; & \; & \; & \; & \; & \; & \; & \; & \cdots & \; \\\; & \; & \; & \; & \; & \; & \; & \; & \; & \sigma_{L}^{2}\end{bmatrix}_{KL}} & (6)\end{matrix}$where each σ_(l) is a variance, and μ₂(n) is given by

$\begin{matrix}{{\mu_{2}(n)} = \begin{bmatrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{bmatrix}^{T}} & (7)\end{matrix}$where b_(j) is a jth dedicated pilot symbol. Note the dimension of μ₂(n)is also KL, where K is a number of dedicated pilot symbols and L is anumber of paths.

Since the uplink feedback error rate is typically within a certainpredictable range, assume that the actual feedback error rate is known(for now), such that MAP detection can be used for the weighting factordetection. For MAP detection, the following optimization problem is tobe solved:

$\begin{matrix}{\hat{w} = {\underset{w}{\arg\;\max}{p\left( {y❘w} \right)}}} & \left( {8a} \right) \\{\hat{w} = {\underset{w}{\arg\;\max}\frac{p\left( {y❘w} \right){p(w)}}{p(y)}}} & \left( {8b} \right) \\{\hat{w} = {\underset{w}{\arg\;\max}p\left( {y❘w} \right){p(w)}}} & \left( {8c} \right)\end{matrix}$

For the MAP detector, we need to make assumptions about p(w) because inone embodiment, p(w) depends on four feedback bits received by the basestation within the most recent four slots. At the device 155, the device155 may record the most recent FBI bits it has sent to the base station.In one embodiment, four bits are recorded. Note that feedback error maynot be independent for slow fading cases. However, to simplify theanalysis, assume that the feedback errors are independent of each other.Then, we calculate p(w).

Similar to the ML detector shown later, for the MAP detector, startingwith equation 8c:

$\begin{matrix}{\hat{w} = {\underset{w}{\arg\;\max}{p\left( {y❘w} \right)}{p(w)}}} & \left( {9a} \right) \\{= {\underset{w}{\arg\;\max}\left\lbrack {{{- \left( {{y(n)} - {\mu_{2}(n)}} \right)^{H}}{C^{- 1}\left( {{y(n)} - {\mu_{2}(n)}} \right)}} + {10{\ln\left( {p(w)} \right\rbrack}}} \right.}} & \left( {9b} \right) \\{= {\underset{w}{\arg\;\max}\left\lbrack {{{- 2}{Real}\left\{ \left( {{y(n)}^{H}C^{- 1}{\mu_{2}(n)}} \right) \right\}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}} & \left( {9c} \right)\end{matrix}$Note that g_(i)(n) replaces h_(i)(n), because h_(i)(n) is not known.Because there is an additive term in equation 9c, μ₂(n) must be scaledby the amplitude ration between the CPICH symbols and the dedicatedpilot symbols.

Therefore, the channel gain ratio between the dedicated pilot symbolsand the CPICH symbols must be estimated. The channel gain ratio a(n) maybe given as:

$\begin{matrix}{{a(n)} = \frac{h_{j}\left( {n,i} \right)}{g_{j}\left( {n,i} \right)}} & (10)\end{matrix}$where h_(j)(n,i) represents the channel gain of the ith path from thejth antenna 130 j for the dedicated pilot symbols, and the g_(j)(n,i)represents the channel gain for the ith path from the jth antenna 130 jfor the common pilot symbols.

For a maximum likelihood (ML) detector, we have the following problem:

$\begin{matrix}{\hat{w} = {\underset{w}{\arg\;\max}{p\left( {y❘w} \right)}}} & \left( {11a} \right) \\{\mspace{20mu}{= {\underset{w}{\arg\;\max}\left\lbrack {{- \left( {{y(n)} - {\mu_{2}(n)}} \right)^{H}}{C^{- 1}\left( {{y(n)} - {\mu_{2}(n)}} \right)}} \right\rbrack}}} & \left( {11b} \right) \\{\mspace{20mu}{= {\underset{w}{\arg\;\max}\left\lbrack {{{- 2}{Real}\left\{ \left( {{y(n)}^{H}C^{- 1}{\mu_{2}(n)}} \right) \right\}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}}} & \left( {11c} \right)\end{matrix}$The problem may be seen as estimating the power ratio between the CPICHsymbols and the dedicated pilot symbols, only needing to scale y(n).

First, the following estimation of the channel gain from the dedicatedpilot symbols:

$\begin{matrix}{{f(n)} = {{\frac{1}{K}{\sum\limits_{i = 1}^{K}{b_{i}^{*}{y_{d2}\left( {n,i} \right)}}}} = {{a\;{\hat{g}(n)}} + (n)}}} & (12)\end{matrix}$where the elements of (n) are joint white Gaussian noise with varianceσ_(l,p) for the lth path.

Thus, it can be shown that

$\begin{matrix}{{p\left( {{f\left( {n,l} \right)}❘a} \right)} = {\frac{1}{\pi\;\sigma_{l,p}^{2}}{\mathbb{e}}^{\lbrack{- \frac{{{{f{({n,l})}} - {a\;{\hat{g}{({n,l})}}}}}^{2}}{\sigma_{l,p}^{2}}}\rbrack}}} & (13)\end{matrix}$where ĝ(n,l) represents the composite channel gain for the lth path (orthe lth component) of ĝ(n).

Since p and l are independent of each other, equation 10 can berewritten as

$\begin{matrix}{{p\left( {{f\left( {n,1} \right)},{f\left( {n,2} \right)},\ldots\mspace{11mu},{{f\left( {n,L} \right)}❘a}} \right)} = {\frac{1}{\pi^{L}{\prod\limits_{l = 1}^{L}\sigma_{l,p}^{2}}}{\mathbb{e}}^{\lbrack{- {\sum\limits_{l = 1}^{L}\frac{{{{f{({n,l})}} - {a\;{\hat{g}{({n,l})}}}}}^{2}}{\sigma_{l,p}^{2}}}}\rbrack}}} & (14)\end{matrix}$

The ML estimate of a is achieved by

$\begin{matrix}{\hat{a} = {\underset{x > 0}{\arg\;\max}\mspace{11mu}{p\left( {f_{1},f_{2},\ldots\mspace{11mu},\left. f_{L} \middle| a \right.} \right)}}} & \left( {15a} \right) \\{= {\underset{x > 0}{\arg\;\max}\left\lbrack {- {\sum\limits_{l = 1}^{L}\;\frac{{{{f\left( {n,l} \right)} - {a\;{\hat{g}\left( {n,l} \right)}}}}^{2}}{\sigma_{l,p}^{2}}}} \right\rbrack}} & \left( {15b} \right) \\{= {\underset{x > 0}{\arg\;\max}\left\lbrack {\sum\limits_{l = 1}^{L}\;\frac{{2a\mspace{11mu}{Real}\left\{ {{f\left( {n,l} \right)}^{*}{\hat{g}\left( {n,l} \right)}} \right\}} - {a^{2}{\;{\hat{g}\left( {n,l} \right)}}^{2}}}{\sigma_{l,p}^{2}}} \right\rbrack}} & \left( {15c} \right)\end{matrix}$

Differentiating equation 15c with respect to a and setting the result tozero, the result is the following ML estimate of a:

$\begin{matrix}{\hat{a} = {\frac{\sum\limits_{l = 1}^{L}\frac{{Real}\left\{ {{f\left( {n,l} \right)}^{*}{\hat{g}\left( {n,l} \right)}} \right\}}{\sigma_{l,p}^{2}}}{\sum\limits_{l = 1}^{L}\frac{{{\hat{g}\left( {n,l} \right)}}^{2}}{\sigma_{l,p}^{2}}} = \frac{\sum\limits_{l = 1}^{L}\frac{{Real}\left\{ {{f\left( {n,l} \right)}^{*}{\hat{g}\left( {n,l} \right)}} \right\}}{\sigma_{l}^{2}}}{\sum\limits_{l = 1}^{L}\frac{{{\hat{g}\left( {n,l} \right)}}^{2}}{\sigma_{l}^{2}}}}} & (16)\end{matrix}$

For the single path case, equation 16 reduces to:

$\begin{matrix}{\hat{a} = {\frac{{Real}\left\{ {{f\left( {n,l} \right)}^{*}{\hat{g}\left( {n,l} \right)}} \right\}}{{{\hat{g}\left( {n,l} \right)}}^{2}} = {{Real}\left\{ \left( \frac{f\left( {n,l} \right)}{\hat{g}\left( {n,l} \right)} \right)^{*} \right\}}}} & (17)\end{matrix}$

Because the power ratio should be same for all paths, two simplerheuristic-based estimators are:

1. Combine power from each path for both the DPCH power and the CPICHpower and then we take the ratio of them, or

2. Take the ratio for each individual path and then do the average ofthe ratio from different paths.

Simulations have demonstrated that the heuristic approach may outperformthe ML approach. In addition, because the first heuristic approach hasless complexity, it is used as an example.

Apply the following estimator for a:

$\begin{matrix}{{\hat{a}}_{w_{1},w_{2}} = \sqrt{\frac{{{f(n)}}^{2}}{{{{{\hat{w}}_{1}{{\hat{g}}_{1}(n)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}(n)}}}}^{2}}}} & (18)\end{matrix}$Equation 18 is just a specific implementation example where we calculatethe total energy from the dedicated pilot symbols and the common pilotsymbols first and then we get the ratio of them. In the denominator ofequation 18, the estimated weighting factors ŵ are used. If ŵ_(i)=w_(i),then the estimates are exact.

Substituting equation 18 into equation 10,

$\begin{matrix}{a_{w_{1},w_{2}} = {\frac{{{f(n)}}^{2}}{{{{{{\hat{w}}_{1}(n)}{{\hat{g}}_{1}(n)}} + {{{\hat{w}}_{2}(n)}{{\hat{g}}_{2}(n)}}}}^{2}} \approx \frac{{{{{{\hat{w}}_{1}(n)}{h_{1}(n)}} + {{{\hat{w}}_{2}(n)}{h_{2}(n)}}}}^{2}}{{{{{{\hat{w}}_{1}(n)}{{\hat{g}}_{1}(n)}} + {{{\hat{w}}_{2}(n)}{{\hat{g}}_{2}(n)}}}}^{2}}}} & (19)\end{matrix}$At the time of estimating a, ŵ_(i)is still not available. According toone aspect of the present invention, a joint power ratio estimator andweighting factor detection method is provided. Instead of estimating theratio separately, calculate the following equation 20 for differentcombinations of w₁ and w₂ (totaling 16 combinations in the embodimentconsistent with Technical Specification 3GPP TS 25.101 V6.1.0 (2003-06),3rd Generation Partnership Project Group Radio Access Network, UserEquipment (UE) radio transmission and reception (FDD) (Release 6), whichis hereby incorporated by reference in its entirety, available from 3GPPc/o ETSI; Mobile Competence Centre; 650, route des Lucioles; 06921Sophia-Antipolis Cedex; FRANCE or on the World Wide Web, for each slot(starting from equation 11c):

$\begin{matrix}{\hat{w} = {\underset{w}{\arg{\;\;}\max}\left\lbrack {{{- 2}\;{Real}\left\{ \left( {{y(n)}^{H}C^{- 1}{\mu_{2}(n)}} \right) \right\}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}} & \left( {20a} \right) \\{\hat{w} = {\underset{w}{{\quad\quad}\arg\mspace{11mu}\max}\left\lbrack {\quad{\quad{{\sum\limits_{l = 1}^{L}\;{{- 2}\mspace{11mu}{Real}\left\{ \frac{{y_{d2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} +}}} \right.}} & \left( {20b} \right) \\\left. {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} \right\rbrack & \;\end{matrix}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l)-is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and

$\begin{matrix}{{\mu_{2}(n)} = \left\lfloor {\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\ldots} \right.} \\{\left. \mspace{481mu}{\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} \right\rfloor^{T},}\end{matrix}$where b_(j) is a jth dedicated pilot symbol, h_(i)(n) are stackedchannel gains from an ith antenna to the device via different paths atan nth slot, and T is a matrix transpose operation. In equation 20b, theratio estimator is integrated into the weights detector. For eachcombination of w₁ and w₂, the ratio is estimated by using the weightscombination under the test. In conventional approaches, the ratio isestimated first and is fixed for all 16 hypotheses.

For the MAP detector, it can be shown that equation 20b becomes(starting from Equation 9c):

$\begin{matrix}{\hat{w} = {\underset{w}{\arg{\;\;}\max\quad}\left\lbrack {{{- 2}\;{Real}\left\{ \left( {{y(n)}^{H}C^{- 1}{\mu_{2}(n)}} \right) \right\}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}} & \left( {21a} \right) \\{\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {\sum\limits_{l = 1}^{L}\;{- {\quad{{{\quad\quad}2\;{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\left\lbrack \begin{matrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{{w\; 1},{w\; 2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{{w\; 1},{w\; 2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{{w\; 1},{w\; 2}}}\end{matrix} \right\rbrack}{\left( \sigma_{l}^{2} \right)} \right\}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right\rbrack}}}}}} \right.}} & {{Equation}\mspace{14mu}\left( {21b} \right)}\end{matrix}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the Second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l)-is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and

$\begin{matrix}{{\mu_{2}(n)} = \left\lbrack {\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\ldots} \right.} \\{\left. \mspace{400mu}{\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} \right\rbrack^{T},}\end{matrix}$where b_(j) is a jth dedicated pilot symbol, h_(i)(n) are stackedchannel gains from an ith antenna to the device via different paths atan nth slot, and T is a matrix transpose operation.

While the preferred embodiments of the present invention have been shownand described, modifications thereof can be made by one skilled in theart without departing from the spirit and teachings of the invention.The embodiments described herein are exemplary only, and are notintended to be limiting. Many variations and modifications of theinvention disclosed herein are possible and are within the scope of theinvention. Accordingly, the scope of protection is not limited by thedescription set out above. Each and every claim is incorporated into thespecification as an embodiment of the present invention.

1. A device, comprising: at least one antenna capable of receiving afirst signal from a first antenna and a second signal from a secondantenna; and a digital signal processor configured to extract a firstweighting factor and a second weighting factor from the first signal andthe second signal while estimating a channel ratio for the first signaland the second signal, and to perform signal combining using the firstweighting factor and the second weighting factor; wherein the channelratio being estimated comprises a channel gain ratio between dedicatedpilot symbols and common pilot symbols.
 2. The device of claim 1,further comprising: an RF unit configured to convert the first signaland the second signal to baseband signals; and wherein the digitalsignal processor is configured to extract the first weighting factor andthe second weighting factor from the baseband signals while estimating achannel ratio for the baseband signals.
 3. The device of claim 2,further comprising: a descrambler configured to descramble the basebandsignals.
 4. The device of claim 1, wherein the digital signal processoris further configured to use an estimation of the channel ratio.
 5. Thedevice of claim 4, wherein the estimation of the channel ratio â isexpressible as: $\begin{matrix}{{{\hat{a}}_{w_{1},w_{2}} = \sqrt{\frac{{{f(n)}}^{2}}{{{{{\hat{w}}_{1}{{\hat{g}}_{1}(n)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}(n)}}}}^{2}}}},} & \;\end{matrix}$ where f(n) is an estimate of a channel gain, ŵ₁ is anestimate for the first weighting factor, ŵ₂ is an estimate for thesecond weighting factor, ĝ₁(n) is an estimate of a first channel gain,ĝ₂(n) is an estimate of a second channel gain, for slot n.
 6. The deviceof claim 5, wherein the estimate of the channel gain f(n) is an estimateof a channel gain for dedicated pilot symbols, wherein the estimate ofthe first channel gain ĝ₁(n) is an estimate of a first channel gain fordedicated pilot symbols, and wherein the estimate of the second channelgain ĝ₂(n) is an estimate of a second channel gain for dedicated pilotsymbols.
 7. The device of claim 5, wherein the digital signal processoris further configured consistent with a maximum likelihood method. 8.The device of claim 7, wherein the maximum likelihood method uses anestimation for weighting factors expressible as:${\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}},$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and ${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 9. The device of claim 5, wherein the digital signalprocessor is further configured consistent with a maximum a priori (MAP)method.
 10. The device of claim 9, wherein the MAP likelihood methoduses an estimation for weighting factors expressible as:$\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and $\begin{matrix}{{\mu_{2}(n)} = \left\lbrack {\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\ldots} \right.} \\{\left. \mspace{400mu}{\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} \right\rbrack^{T},}\end{matrix}$ where b_(j) is a jth dedicated pilot symbol, h_(i)(n) arestacked channel gains from an ith antenna to the device via differentpaths at an nth slot, and T is a matrix transpose operation.
 11. Thedevice of claim 1, wherein the digital signal processor is furtherconfigured consistent with a maximum likelihood method.
 12. The deviceof claim 11, wherein the maximum likelihood method uses an estimationfor weighting factors expressible as:${\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}},$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and ${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 13. The device of claim 1, wherein the digital signalprocessor is further configured consistent with a maximum a priori (MAP)method.
 14. The device of claim 13, wherein the MAP method uses anestimation for weighting factors expressible as:$\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and $\begin{matrix}{{\mu_{2}(n)} = \left\lbrack {\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\ldots} \right.} \\{\left. \mspace{400mu}{\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} \right\rbrack^{T},}\end{matrix}$ where b_(j) is a jth dedicated pilot symbol, h_(i)(n) arestacked channel gains from an ith antenna to the device via differentpaths at an nth slot, and T is a matrix transpose operation.
 15. Thedevice of claim 1, wherein the device is configured as one or more of acell phone or a computer.
 16. A device, comprising: at least one antennameans capable of receiving a first signal from a first antenna and asecond signal from a second antenna; means for extracting a firstweighting factor and a second weighting factor from the first signal andthe second signal while estimating a channel ratio for the first signaland the second signal; and means for performing signal combining usingthe first weighting factor and the second weighting factors wherein thechannel ratio being estimated comprises a channel gain ratio betweendedicated pilot symbols and common pilot symbols.
 17. The device ofclaim 16, further comprising: means for converting the first signal andthe second signal to baseband signals, wherein the means for extractingthe first weighting factor and the second weighting factor from thefirst signal and the second signal while estimating a channel ratio forthe first signal and the second signal includes means for extracting thefirst weighting factor and the second weighting factor from the basebandsignals while estimating a channel ratio for the baseband signals. 18.The device of claim 17, further comprising: means for descrambling thebaseband signals.
 19. The device of claim 16, wherein the means forextracting the first weighting factor and the second weighting factorfrom the first signal and the second signal while estimating a channelratio for the first signal and the second signal is further configuredto use an estimation of the channel ratio.
 20. The device of claim 19,wherein the estimation of the channel ratio â is expressible as:${{\hat{a}}_{w_{1},w_{2}} = \sqrt{\frac{{{f(n)}}^{2}}{{{{{\hat{w}}_{1}{{\hat{g}}_{1}(n)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}(n)}}}}^{2}}}},$where f(n) is an estimate of a channel gain, ŵ₁ is an estimate for thefirst weighting factor, ŵ₂ is an estimate for the first weightingfactor, ĝ₁(n) is an estimate of a first channel gain, ĝ₂(n) is anestimate of a second channel gain, for slot n.
 21. The device of claim20, wherein the estimate of the channel gain f(n) is an estimate of achannel gain for dedicated pilot symbols, wherein the estimate of thefirst channel gain ĝ₁(n) is an estimate of a first channel gain fordedicated pilot symbols, and wherein the estimate of the second channelgain ĝ₂(n) is an estimate of a second channel gain for dedicated pilotsymbols.
 22. The device of claim 20, wherein the means for extractingthe first weighting factor and the second weighting factor from thefirst signal and the second signal while estimating a channel ratio forthe first signal and the second signal is further configured consistentwith a maximum likelihood method.
 23. The device of claim 22, whereinthe maximum likelihood method uses an estimation for weighting factorsexpressible as:${\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}},$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and ${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 24. The device of claim 20, wherein the means for extractingthe first weighting factor and the second weighting factor from thefirst signal and the second signal while estimating a channel ratio forthe first signal and the second signal is further configured consistentwith a maximum a priori (MAP) method.
 25. The device of claim 24,wherein the MAP method uses an estimation for weighting factorsexpressible as:$\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and $\begin{matrix}{{\mu_{2}(n)} = \left\lbrack {\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\ldots} \right.} \\{\left. \mspace{400mu}{\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} \right\rbrack^{T},}\end{matrix}$ where b_(j) is a jth dedicated pilot symbol, h_(i)(n) arestacked channel gains from an ith antenna to the device via differentpaths at an nth slot, and T is a matrix transpose operation.
 26. Thedevice of claim 16, wherein the means for extracting the first weightingfactor and the second weighting factor from the first signal and thesecond signal while estimating a channel ratio for the first signal andthe second signal is further configured consistent with a maximumlikelihood method.
 27. The device of claim 26, wherein the maximumlikelihood method uses an estimation for weighting factors expressibleas:${\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}},$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and ${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 28. The device of claim 16, wherein the means for extractingthe first weighting factor and the second weighting factor from thefirst signal and the second signal while estimating a channel ratio forthe first signal and the second signal is further configured consistentwith a maximum a priori (MAP) method.
 29. The device of claim 28,wherein the MAP method uses an estimation for weighting factorsexpressible as:$\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and $\begin{matrix}{{\mu_{2}(n)} = \left\lbrack {\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\ldots} \right.} \\{\left. \mspace{400mu}{\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} \right\rbrack^{T},}\end{matrix}$ where b_(j) is a jth dedicated pilot symbol, h_(i)(n) arestacked channel gains from an ith antenna to the device via differentpaths at an nth slot, and T is a matrix transpose operation.
 30. Thedevice of claim 16, wherein the device is configured as one or more of acell phone or a computer.
 31. A communications system, comprising: abase station, comprising: a first antenna configured to transmit a firstsignal using a first weighting factor; and a second antenna configuredto transmit a second signal using a second weighting factor; and adevice, comprising: at least one antenna capable of receiving the firstsignal from the first antenna and the second signal from the secondantenna; and a digital signal processor configured to extract a firstweighting factor and a second weighting factor from the first signal andthe second signal while estimating a channel ratio for the first signaland the second signal, and to perform signal combining using the firstweighting factor and the second weighting factor; wherein the channelratio being estimated comprises a channel gain ratio between dedicatedpilot symbols and common pilot symbols.
 32. The communications system ofclaim 31, wherein the device further comprises: an RF unit configured toconvert the first signal and the second signal to baseband signals; andwherein the digital signal processor is configured to extract the firstweighting factor and the second weighting factor from the basebandsignals while estimating a channel ratio for the baseband signals. 33.The communications system of claim 32, wherein the device furthercomprises: a descrambler configured to descramble the baseband signals.34. The communications system of claim 31, wherein the digital signalprocessor is further configured to use an estimation of the channelratio.
 35. The communications system of claim 34, wherein the estimationof the channel ratio â is expressible as:${{\hat{a}}_{w_{1},w_{2}} = \sqrt{\frac{{{f(n)}}^{2}}{{{{{\hat{w}}_{1}{{\hat{g}}_{1}(n)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}(n)}}}}^{2}}}},$where f(n) is an estimate of a channel gain, ŵ₁ is an estimate for thefirst weighting factor, ŵ₂ is an estimate for the first weightingfactor, ĝ₁(n) is an estimate of a first channel gain, ĝ₂(n) is anestimate of a second channel gain, for slot n.
 36. The communicationssystem of claim 35, wherein the estimate of the channel gain f(n) is anestimate of a channel gain for dedicated pilot symbols, wherein theestimate of the first channel gain ĝ₁(n) is an estimate of a firstchannel gain for dedicated pilot symbols, and wherein the estimate ofthe second channel gain ĝ₂(n) is an estimate of a second channel gainfor dedicated pilot symbols.
 37. The communications system of claim 35,wherein the digital signal processor is further configured consistentwith a maximum likelihood method.
 38. The communications system of claim37, wherein the maximum likelihood method uses an estimation forweighting factors expressible as:${\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}},$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and ${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 39. The communications system of claim 35, wherein thedigital signal processor is further configured consistent with a maximuma priori (MAP) method.
 40. The communications system of claim 39,wherein the MAP method uses an estimation for weighting factorsexpressible as:$\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and $\begin{matrix}{{\mu_{2}(n)} = \left\lbrack {\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\ldots} \right.} \\{\left. \mspace{400mu}{\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} \right\rbrack^{T},}\end{matrix}$ where b_(j) is a jth dedicated pilot symbol, h_(i)(n) arestacked channel gains from an ith antenna to the device via differentpaths at an nth slot, and T is a matrix transpose operation.
 41. Thecommunications system of claim 31, wherein the digital signal processoris further configured consistent with a maximum likelihood method. 42.The communications system of claim 41, wherein the maximum likelihoodmethod uses an estimation for weighting factors expressible as:${\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}},$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and ${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 43. The communications system of claim 31, wherein thedigital signal processor is further configured consistent with a maximuma priori (MAP) method.
 44. The communications system of claim 43,wherein the MAP method uses an estimation for weighting factorsexpressible as:$\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and $\begin{matrix}{{\mu_{2}(n)} = \left\lbrack {\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}\mspace{14mu}\ldots} \right.} \\{\left. \mspace{400mu}{\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} \right\rbrack^{T},}\end{matrix}$ where b_(j) is a jth dedicated pilot symbol, h (n) arestacked channel gains from an ith antenna to the device via differentpaths at an nth slot, and T is a matrix transpose operation.
 45. Thecommunications system of claim 31, wherein the device is configured asone or more of a cell phone or a computer.
 46. A method for improvingcommunications, the method comprising: receiving a first signal and asecond signal; extracting a first weighting factor and a secondweighting factor from the first signal and the second signal whileestimating a channel ratio for the first signal and the second signal;and performing signing combining using the first weighting factor andthe second weighting factor; wherein the channel ratio being estimatedcomprises a channel gain ratio between dedicated pilot symbols andcommon pilot symbols.
 47. The method of claim 46, further comprising:converting the first signal and the second signal to baseband signals;wherein extracting the first weighting factor and the second weightingfactor from the first signal and the second signal while estimating thechannel ratio for the first signal and the second signal comprisesextracting the first weighting factor and the second weighting factorfrom the baseband signals while estimating a channel ratio for thebaseband signals.
 48. The method of claim 47, further comprising:descrambling the baseband signals.
 49. The method of claim 46, whereinextracting the first weighting factor and the second weighting factorfrom the first signal and the second signal while estimating the channelratio for the first signal and the second signal further comprises usingan estimation of the channel ratio.
 50. The method of claim 49, whereinusing the estimation of the channel ratio further comprises using anestimation of the channel ratio â expressible as: $\begin{matrix}{{{\hat{a}}_{w_{1},w_{2}} = \sqrt{\frac{{{f(n)}}^{2}}{{{{{\hat{w}}_{1}{{\hat{g}}_{1}(n)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}(n)}}}}^{2}}}},} & \;\end{matrix}$ where f(n) is an estimate of a channel gain, ŵ₁ is anestimate for the first weighting factor, ŵ₂ is an estimate for the firstweighting factor, ĝ₁(n) is an estimate of a first channel gain, ĝ₂(n) isan estimate of a second channel gain, for slot n.
 51. The method ofclaim 50, wherein the estimate of the channel gain f(n) is an estimateof a channel gain for dedicated pilot symbols, wherein the estimate ofthe first channel gain ĝ₁(n) is an estimate of a first channel gain fordedicated pilot symbols, and wherein the estimate of the second channelgain ĝ₂(n) is an estimate of a second channel gain for dedicated pilotsymbols.
 52. The method of claim 50, wherein extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal further comprises extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal consistent with a maximum likelihoodmethod.
 53. The method of claim 52, wherein extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal consistent with the maximum likelihoodmethod further comprises extracting the first weighting factor and thesecond weighting factor from the first signal and the second signalwhile estimating the channel ratio for the first signal and the secondsignal consistent with the maximum likelihood method using an estimationfor weighting factors expressible as:${\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}},$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and ${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 54. The method of claim 50, wherein extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal further comprises extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal consistent with a maximum a priori (MAP)method.
 55. The method of claim 54, wherein extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal consistent with the MAP method furthercomprises extracting the first weighting factor and the second weightingfactor from the first signal and the second signal while estimating thechannel ratio for the first signal and the second signal consistent withthe MAP method using an estimation for weighting factors expressible as:$\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 56. The method of claim 46, wherein extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal further comprises extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal consistent with a maximum likelihoodmethod.
 57. The method of claim 56, wherein extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal consistent with the maximum likelihoodmethod further comprises extracting the first weighting factor and thesecond weighting factor from the first signal and the second signalwhile estimating the channel ratio for the first signal and the secondsignal consistent with the maximum likelihood method using an estimationfor weighting factors expressible as:${\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}\frac{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\frac{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}} \\\cdots \\\frac{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)}{a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}}} \right\rbrack}},$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ₁ is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, and ${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i)(n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.
 58. The method of claim 46, wherein extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal further comprises extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal consistent with a maximum a priori (MAP)method.
 59. The method of claim 58, wherein extracting the firstweighting factor and the second weighting factor from the first signaland the second signal while estimating the channel ratio for the firstsignal and the second signal consistent with the MAP method furthercomprises extracting the first weighting factor and the second weightingfactor from the first signal and the second signal while estimating thechannel ratio for the first signal and the second signal consistent withthe MAP method using an estimation for weighting factors expressible as:$\hat{w} = {\underset{w}{\arg\;\max}\left\lbrack {{\sum\limits_{l = 1}^{L}{{- 2}{Real}\left\{ \frac{{y_{d\; 2}\left( {n,l} \right)}^{H}\begin{bmatrix}{{d(1)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\{{d(2)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}} \\\cdots \\{{d(K)}\left( {{{\hat{w}}_{1}{{\hat{g}}_{1}\left( {n,l} \right)}} + {{\hat{w}}_{2}{{\hat{g}}_{2}\left( {n,l} \right)}}} \right)a_{w_{1},w_{2}}}\end{bmatrix}}{\sigma_{l}^{2}} \right\}}} + {a_{w_{1},w_{2}}{\mu_{2}(n)}^{H}C^{- 1}{\mu_{2}(n)}} + {10{\ln\left( {p(w)} \right)}}} \right\rbrack}$where ŵ₁ is an estimate for the first weighting factor, ŵ₂ is anestimate for the second weighting factor, ĝ₁(n,l) is an estimate of afirst channel gain for dedicated pilot symbols, ĝ₂(n,l) is an estimateof a second channel gain for dedicated pilot symbols, n is a slot, l isa path index, σ_(l) is a variance, C⁻¹ is an inverse of a noise variancematrix, d(l) is an lth dedicated pilot signal, K is a number ofdedicated pilot symbols, L is a number of paths, H is a complexconjugate operation, ln(x) is natural logarithm of x, p(w) is a priorprobability of using a given weighting factor, and${{\mu_{2}(n)} = \left\lfloor \begin{matrix}{\frac{1}{\sqrt{2}}{b_{1}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & {\frac{1}{\sqrt{2}}{b_{2}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}} & \cdots & {\frac{1}{\sqrt{2}}{b_{K}\left( {{w_{1}{h_{1}(n)}} + {w_{2}{h_{2}(n)}}} \right)}}\end{matrix} \right\rfloor^{T}},$ where b_(j) is a jth dedicated pilotsymbol, h_(i) (n) are stacked channel gains from an ith antenna to thedevice via different paths at an nth slot, and T is a matrix transposeoperation.